कलौ सङ्कीर्त्य केशवम्

ध्यायन् कृते यजन् यज्ञैः त्रेतायां द्वापरेऽर्चयन्।
यदाप्नोति तदाप्नोति कलौ सङ्कीर्त्य केशवम्॥
dhyāyan kṛte yajan yajñaiḥ tretāyāṁ dvāpare’rcayan|
yadāpnoti tadāpnoti kalau saṅkīrtya keśavam||
The religious merit which accrues from meditating on God in Krita yuga, from performing yagnas in Treta yuga, from ritual worship in Dvapara yuga, can be obtained by praising and praying to Kesava in Kali yuga..

सङ्कीर्त्य नारायणशब्दमात्रम्

आर्ता विषण्णाः शिथिलाश्च भीताः घोरेषु च व्याधिषु वर्तमानाः।
सङ्कीर्त्य नारायणशब्दमात्रं विमुक्तदुःखाः सुखिनो भवन्तु॥
ārtā viṣaṇṇāḥ śithilāśca bhītāḥ ghoreṣu ca vyādhiṣu vartamānāḥ|
saṁkīrtya nārāyaṇaśabdamātram vimuktaduḥkhāḥ sukhino bhavantu||

This shloka again expounds the power and importance of नामसङ्कीर्तनम् (nāmasaṅkīrtanam), which is one of the most relevant and possible methods of worship in this age of Kali (कलियुगम्).

An oft-quoted example of the power of nāmasaṅkīrtanam is that of Ajamila. Read more about Ajamila in wikipedia.